If cos theta + cos 7theta + cos 3theta + cos | vedclass

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Question

(c) Combining $	heta $ and $7	heta $, $3	heta $ and $5	heta $, we get

$2\cos 4	heta (\cos 3	heta + \cos 	heta ) = 0$

==> $4\cos 4	het

Vedclass · Accepted Answer

$\frac{{n\pi }}{8}$

Vedclass · Answer

(c) Combining $	heta $ and $7	heta $, $3	heta $ and $5	heta $, we get

$2\cos 4	heta (\cos 3	heta + \cos 	heta ) = 0$

==> $4\cos 4	heta \,\cos 2	heta \cos 	heta = 0$

==> $4\frac{1}{{{2^3}\sin 	heta }}$ $(\sin {2^3}	heta ) = 0$; $\sin 8	heta = 0$.

Hence $	heta = \frac{{n\pi }}{8}$.

If $\cos \theta + \cos 7\theta + \cos 3\theta + \cos 5\theta = 0$, then $\theta $

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